Many applications for processing in industry require mixing two or more components to make a mixture homogeneous. Generally, such mixing is performed using internal mechanical devices immersed in the fluid, such as paddles or impellers. However, this type of mixing has some limitations and drawbacks. In certain applications, such as the chemical or biotechnological arts, it is desirable to have mixing processes that are sterile and free of contamination from the outside environment. The introduction of mechanical devices into a fluid can introduce contaminants, thus requiring re-sterilization of such devices each time they are used. Such a re-sterilization process can have added costs and delays that are not desirable. Also, re-sterilization requires high quality components that can withstand the added wear, which can also increase costs.
Additionally, some fluid mixtures have delicate components that are prone to shear. For example, an impeller moving quickly through a fluid can decrease cell culture viability or cause cell death therefore decreasing culture productivity. Thus, it is useful to have a mixing apparatus without the use of mechanical devices that might introduce contaminants and/or risk damaging the components of the fluid itself.
Further, mixing applications that use recirculating tubes leading to a peristaltic pump, for example, are susceptible to ruptures or leaks in those tubes or related couplings. The integrity of tubing, conduits and coupling seals can be compromised by fluid pressure and other factors.
Alternatively, mixing is performed by external movement of an entire fluid vessel, such as rocking or rotating. However, moving an entire fluid vessel with all its ports, probes, and connections is sometimes impractical and often requires large cumbersome devices. It is therefore desirable to provide a mixing system that does not compromise or interfere with the ports, probes and connections of the fluid vessel, or require bulky apparatus to accomplish the task.